Liquid-level indicator



Feb. 28, 1928.

F. G. FOLBERTH ET AL A LIQUID LEVEL INDICATOR Filed May 25, 1922Jayce/ww' Patented Feb. 28, 1928.

.UNITED STATES PATENT OFFICE.

. FREDERICK G. FOLDERTH .AND WILLIAM M.` FOLBERTH, F CLEVELAND, OHIO.

LIQUID-LEVEL INDICATOR.

Application led May 25, 1922. Serial No. 563,620.

The invention relates to indicators for liquid fuel supply systems forhydro-carbon motors. l

Itis the primary object 'of the invention to v In the drawings, F

1 is a' schematic view showing theliqui fuel supply system 5 provide anindicatin mechanism having 'a' for a hydro-carbonmotor of an automobilesight gauge that wil accurately indicate\with the invention appliedthereto. WV l atever quantity of liquid fuel may be within the supplytank of a liquid fuel sup'- ply system of a hydro-carbon motor.

A further `object of the inventionv is to provide improved means forpositioning the gauge upon a vehicle so that it can be readilymanipulated by the operator of the vehicle for indicating the quantityof liquid fue-l in the supply tank thereof.

It is a furtheiolnect of t-lie invention to provide an improved'liquidlevel indicating means comprising a gauge and connections betweenI thesame and the supply tank in which a portion of the liquid fuel iseinployed as an indicating medium by forcing a portion thereof `upwardlyin the gauge, thus eliminating the necessity of charging the gauge witha fluid separate and distinct '25 from the liquid fuel or providingdelicate and intricate mechanism for indicating the quantity ofliquidrfuel within the supply tank.

`The invention is particularly adapted for 30 use on automobiles orother motor operated frequently happens that the driver of anautomobile' or other motor operated conveyance exhausts the liquid fuelfrom the supply Vtank'unexpectedly at a point remote from a source offuel supply and is unable to further operate'the motor until afresh'supply of fuel can be obtained and the purpose of the invention isto provide an indicator that will accurately indicate the quantity offuel within the fuel supply tank so that the operator of the motor maybe apprised of the quantity* of fuel within the fuel supply tank, thusavoidin the dai'igerof completely exhausting the iquid fuel from thefuel supply tank and thereby becoming stranded at a point remote from asource of fuel supply.

Other objects of the invention will appear from the followingdescription which is directed to the preferred embodiment of theinvention, reference being had to the accompanying drawings which form apart of the specification, the features of novelty being v is utilizedfor drawing the liquid fuel from i Fig. 2 is an enlarged detail viewshowing the cylinder and piston for forcing the liquid fuel'into theauge, a fragment of the sup ply tank also eing shown.

Fig. 3 is a schematic view similar to Fig. 1 showing a modified form ofthe-invention. Fig. 4 'is a detail sectional view of a further modifiedform of the invent-ion.-

1n tlie embodiment of the vinvention as illustrated in tlie drawings theimproved indicator mechanismfor indicating the quantit-y of liquid fuelwithin the supply tank is shown asapplied to the tank of a liquid fuelsupplyV system lfor hydro-carbon motors of a conventional type.l

.eferring to thedrawings, for a more detailed description of theinvention, reference character 10 indicates the liquid fuel supply'tank, which in the. drawings is, although not necessarily so, shown ascarried at the rear of an automobile.` This supply tank 10 is shown asbelow the levelof the carburetor 11 of a motor, the intake manifold 12Aof which communicates with the carburetor for supplying gaseous fuel tothe motor. A v acuum or auxiliary fuel tank 13 of conventional form isplaced as shown in the drawings for feeding liquid fuel from tank 1() tothe carburetor 11 by gravity through the usual feed line 14. In commonpractice Where vacuum or auxiliary tanks of the type as designated byreference character 13 are used, the suction i'oduced in the intakemanifold by the action of the motor pistons the low level supply tank 10to the vacuum or auxiliary fuel tank 13 through the pipe 15 leading fromthe intake manifold 12 to the vacuum or auxiliary fuel tank 13, theconnection between the vacuum or auxiliary fuel tank 13and Athe supplytank 10 being formed through the liquid fuel linc 16. The` fuel line 16preferably enters the supply tank 10 as shown in the drawing at a poi-ntadjacent the bottom of the tank as at 16a for the purpose of being ableto quite completely exhaust the liquid fuel within the tank when vacuumis formed in the fuel line 16 in the manner before referred to.

The fuel line 16 however, may be introduced into the supply tank 1()through theV top thereof and projected downwardly through the tank to apoint adjacent the bottom lthereof, if referred. .ln the form of theinvention as il ustrated in Figs. 1 and 2 a graduated gauge 17 issecured to the instrument board 18 of the automobile by bracket 19. Pipe20 forms a connection between the lower extremity of gauge 17 andcylinder 21 within the supply tank 10. Pipe 20 is preferably introducedinto tank 10 from the top thereof as illustrated in Fig. 1.

The means for forcing liquid fuel from the supply tank 10 upwardly toand into gauge 17 for the purpose of indicating the quantity of liquidfuel within the tank will now be described.

A cylinder 21 having cover 29 is placed within the tank 10 and securedto the bottom thereof in any suitable manner. l/Vithin the cylinder andadapted to have reciprocal movement therein is piston 23. At a pointimmediately above the upper face of piston 23 when at its lowermostposition within the cylinder is port 22 through the wall of the cylinderfor admission of liquid fuel from the supply 'tank into the cylinder andabove the upper face of piston 23. In the bottom of the cylinder isanother port 22 which permits the admission of liquid fuel from the-supply tank beneath the piston 23. The object of this port 22 in thebottom of the cylinder is to eliminate the formation of a vacuum whichin turn would prevent the operation of the piston. Piston 23 has affixedto the upper face thereof rod 24 which may be made of any suitablematerial such as brass, for example, and to the upper extremity of therod is affixed a soft iron solenoid core 25, which is adapted to vmoveupwardly within the solenoid 26 secured to the top wall of the supplytank and preferably on the interior thereof. Circuit wires 27, 28leading from battery 27h to the solenoid are provided for energizing thesolenoid and are preferably brought to a convenient point for control ofthe circuit by the operator of the device, as for example, theinstrument board 18, where the wires are shown leading to the switchmechanism o )erated by push button 27, preferably of t e type of switchnormally open and adapted to close the circuit by pressure upon the pushbutton 27a. The soft iron core 25 affixed to the upper extremity of rod24 extends a short distance into the central opening of solenoid 26 inorder that the solenoid when energ d may act as a magnetupon the coreand draw the piston upwardly of the cylinder 21. A helical spring 30surrounds the lower end of pisvton rod 24C being inserted between the uper side of the piston 23 and thevunderside o the top closure 29 of thecylinder, thus tendingv normally to force the piston downwardly ofnecessary for a zero readin A glass will increase the` heig t of theiu'id the cylinder and being effective to depress the piston to thelowermost extremity of its movement in the cylinder whenever the magnetis de-energized. lVhile the relative diameter of the interior orrecording portion of the gauge 17 in relation to the pipe 20 and thepiston displacement may vary, thus necessitating variations in thegraduation of the recording scale thereon for different installations,it is desirable in constructing the apparatus herein described that thenormal and maximum displacement of the piston, as determine-d by themaximum amount of Huid that may be discharged by al single maximumdischarge stroke of the piston, shall be exactly sufficient to fill theinterior of the pipe line 20 and cause the column of fluid therein tostand at what will preferably be marked as the zero graduation on thereading glass or indicator gauge 17. It will be seen that when themagnet 26 is de-energized and the piston depressed in the cylinder theinlet port 22 will be uncovered so that the fluid within the tank 10 mayenter the cylinder 21 through inlet port 22 and will rise in thecylinder 21 and the vertical line 33 of pipe 20 to the level of theliquid within the tank. Assuming, for example, that the level of theliquid within the tank 10-is only suicient to fill the cylinder 21 abovethe piston but does not rise above the lower extremity of the verticalportion 33 of t-he pipe 20, the .actuation of" the piston by the meansdescribed will result in the liquid column within the gauge coming onlyto the zero reading, thus indicating to the operator that the supply offluid fuel is almost exhausted. Any increment of fuel within the tank'lOabove the amount of the before described reading on the gauge glasskwill obviously, prior to the actuation of the piston cause the fluidIcolumn tostand to a corresponding height in the vertical vpipe 33 abovesuch zero reading height, lals described, and hence, when the piston 23is actuated the volume of fluid stan-ding within the vertical portion 33of the line 20 will be added to the zero reading of the fluid column inthe gauge glass 17. If the diameter of the interior of the gauge glass17 equals the diameter of the interior of the vertical line 33 of pipeobviously, any increment of liquid fuel within the tank above the amounton the gauge column within the gauge ,glass an equal amount and thegauge lass may be accordingly graduated to in icate the fuel tank 1capacity. Obviously, variations of the capacity of tank 10, the verticalpipe 33 and the capacity of the interior opening in the gauge glass 17,will re uire corresponding correct-ions on the gra uate-d readings ofthe gauge -glass to indicate the correct tank capacity. As long as thepiston 23 remains in its elevated position, which will be so long as themagnetcontinues to be enerized by the closing of the switch 27, thevfliiid will be retained in its elevated position in the line, but whenthe switch 27 is opened and the solenoid de-energized the spring 30 willreturn the piston 23 to its lowermost point 'invention whch'is adaptableto gravity or compression liquid fuel supply systems for hydro-carbonmotors and as shown in the drawings is applied to an automobile. In thisform of the invention a return pipe 34 is provided which connects theupper extremity of gauge 17 with fuel `supply tank 10 and isA forlthepurpose of e ualizing pressure wit-hin the gasoline tan and in the gaugeand its connections with the tank. Pressure for feeding fuel direct tothe carburetor may be obtained by means of the han'd operated pumpillustrated in which the barrel is designated by the reference character35 connected with the tank by air line 36 37 being the piston rod and 38the handle thereof.

-In Fig. 4 is shown a modified form of the invention of Figs. 1 to 3inclusive, in which the piston for actuating the fluid column and itsoperating means is shown installed on the outside of the fuel supplytank, in this instance being attached to the bottom of the tank. In thismodified form of the invention the solenoid 26 is supported in a casing39 affixed in any suitable manner to the bottom of tank 10. Cylinder 21asupported within the solenoid 26a carries piston 40 therein which isadapted to have reciprocal movement within the cylinder. Byass 41leading from the bottom of the supp y tank 10 through the side wall ofcylinder 21 lat a point immediately above the pla-ne of the upper faceof piston-40 when at its lowermost point of movement Within the clin'der is for the purpose of conducting liquid fluid from the tank 10into and filling the cylinder 21. The by-pass 41 has a branch extension41 which enters the bottom of the casing 39 as shown at 42 andcommunicates with the cylinder 21 below the piston 40.4 This extension41 permits the liquid to flow into the cylinder 21* below the piston 40as the piston is raised by the solenoid. Helical spring 42 interposedbetween the top of casing 39 and the upper face of piston 40 is attachedto the top of the casing 39 and piston 40 at its respective ends andtends to forcethe piston downwardly of cylinder 21l when solenoid 26a isde-energized. Circuit wires 43, 44 are provided for energizing solenoid26. In thls modified form of the invention the pi'ston40vwithin c linder2la is formed of any suitable material such as soft iron, for example,to form a core for co-operation with the solenoid 26a. In this form ofthe invention the pipe 33 is tapped through the tank 10 at a pointpreferably at the topthereof, as at 45. In operation the piston formingthe core for solenoid 26a for co-operation therewith will be drawnupwardly within cylinder 21V when the solenoid is energized, thusfunctioning as a pump piston and forcing the liquid fuel upwardlyandthrough the tube 33, as described, with relation to the device, as shownin Fig. 1. In-

termediate the bottom of casing 39 and the bot-torn of solenoid 26aL andsurrounding cyl-.l

inder 21a is placed an insulating element 46. Obviously, the circuitcontrolling-this solenoid as Well as the circuit controlling thesolenoid sho-wn in Fig. 3 will be provided with suitable means,vasillustrated by the switch button 27a of Fig. 1, for operating thesolenoid, and it will be seen that the invention as illustrated intheforms of Figs. 1, 3 and 4 will furnish a ready and convenient meansby which the operator of a motor car, for example, may quicklyVdetermine the height of fuel within the supply tank by causing the gaugemechanism to register the same, and it will be further seen that areading from the gauge may be obtained at any time when the gauge isvisible to the operator by first causing the measuring piston to beactuated by the closing of the circuit for actuating the solenoid,whereuponl in the manner described, a correct reading of the hei htofthe fuel fluid within the supply tan should be correctly recorded inthe gauge and readable therein as in an ordinary liquid gauge orthermometer. Obviously, the gauge may be suitably graduated as may bedesired and in correspondence with the capacity of the tank inconnection .with which it is to be used'.

In order that the invention might be understood,l we have shown thedetails of the preferred embodiment of our invention, but 1t is-notdesired to be limited to the mere details of construction, for it willbe apparent that persons skilled in the art may resort to variousmodifications without departing from the purpose and spirit of theinvention.

We claim:

1. In a liquid gaugeA for liquid fuel supply systems for hydro-'carbonmotors, the combination with a container, of a cylinder having anopening in the lateral wall thereof near one end of the cylinder, and incommubeing an opening having a venting function at the said one end ofthe-said cylinder on one side of the piston, means for compressing airwithin the container, a gauge, a pipe connecting the gauge withtheinterior of the cylinder, and a pipe connecting the gauge with theinterior of the container exteriorly of said cylinder whereby toequalize the air pressure in the said container and gauge.

2. In a liquid gauge, the combination with a container, of a closedcylinder affixed to the bottom of the container, a piston carried withinthe cylinder and adapted to have reciprocal movement therein, therebeing means for establishing communication from the interior of thecontainer to the interior of the cylinder at points immediately aboveand below the corresponding faces of the piston when at its lowest pointof movement within the cylinder, a gauge spaced from the container, apipe communicating with the top of the cylinder and the bottom of thegauge, a piston rod 'adapted to have free reciprocal movement throughlthe top of the cylinder and aiixed to the piston, a core carried by theupper extremityof the rod, a solenoid carried by the top of thecontainer and surrounding the upper part of said core, aspringsurrounding the lower portion of the piston rod and'interposedbetween the upper face of the piston and the inner face of the top ofthe cylinder, and means for controlling the energizatien of thesolenoid. l

3. In a liquid gauge, the combination with a tank of a cylinder havingcommunication with the tank and being adapted to receive liquidtherefrom, apiston mounted to reciprocate in said cylinder, a gaugespaced from the tank, 4a pipe connecting the cylinder and the gauge, andactuated means for reciprocally moving the piston Within the cylinderand pumping said liquid therefrom, the displacement of said pistonwithin the cylinder being substantially equal to the capacity of thepipe connecting the tank andthe gauge.

4. In a liquid gauge, the combination with a tank of a cylinder havingcommunication with the tank and being adapted to receive liquidtherefrom, a piston mounted to reciprocate in said cylinder, a gaugespaced from the tank, a pipe connecting the cylinder and the gauge, andactuated means or reciprocally moving the piston within the cylinder andpumping said liquid therefrom,.the said gauge being provided with a zerodesignation and the capacity of the pipe connecting the cylinder andthe'gauge including the capacity of the gauge to the zero 4designationthereon being equal to the maximum displacement vof thepiston.

5. In a liquid gauge, the combination with agcontainer, of a cylinderwithin the container andl having an opening in the lateral walltherefnear one end of the cylinder, a piston normally positioned at saidend and adapted to close the opening when moved toward the other end, agauge spaced from the container, a pipe connecting the gauge.

and the cylinder, and an electro-magnet spaced from one end of thecylinder and adapted, when energized, to draw the piston toward it.

6. In a liquid gauge, the combination with a tank of a cylinder havingcommunication with the tank, a piston in said' cylinder, a gauge spacedfrom the tank, a pipe connecting the cylinder and gauge, anelectro-magnetic means for reciprocally moving the piston Within thecylinder, the displacement of said piston within the cylinder beingsubstantially equal to the capacity of the pipe connecting the cylinderand gauge.

7 In a liquid gauge, the combination with a tank, of a cylinder and apiston therein, said cylinder having an opening in the wall thereof forcommunication with the tank, a

gauge spaced from the tank, a pipe line con-

